1. Field of the Invention
The field of the invention relates to devices for the administration of medication and, more particularly, to nasal syringes in which the travel of the plunger is controlled by a stop mechanism.
2. Brief Description of the Prior Art
A number of medications may be effectively administered through the nasal passages. Devices have accordingly been developed for this purpose, such as that described in U.S. Pat. No. 5,601,077. Nasal syringes of more conventional construction include a cylindrical barrel having a blunt tip portion for insertion into a nostril. A piston is positioned within the barrel. A plunger extends from the end of the barrel opposite to the blunt tip. The position of the piston within the barrel is controlled by the plunger. A flange may be provided on one end of the plunger to facilitate its use.
Nasal syringes are often supplied to users pre-filled with medication. Whether prefilled or not, it may be desirable to administer selected, and usually equal volumes of medication to each nostril. U.S. Pat. No. 4,962,868 discloses the use of a telescoping tube assembly which is designed for expelling the contents of a nasal syringe in two controlled doses.
While syringes often include graduations, it remains difficult for users to administer equal doses of medication to each nostril using conventional syringes. As such syringes are relatively inexpensive to manufacture and pre-fill, and are mass-produced, they have certain advantages over syringes which may be specifically designed for self-administration.